Modern consumer electronics products trend toward higher speed operation, multi-function and portability. Thus, integrated circuits and passive devices within electronics product become more dense from each other gradually so as to make radiated emissions interacted between electronic devices more severely. Particularly, a printed circuit board (PCB) likely generates serious radiated emissions by formation of antenna structure as long as work frequency achieves gigahertz (GHz) level.
A conventional method for measuring PCB radiated emissions is to receive radiated emissions by an antenna array and to analyze radiated emissions of an object via a data processor. However, the object and the antenna array must be spaced apart by at least one tenth wavelength of scanning frequency in order to maintain a better characteristic in receiving emissions. Besides, the conventional method must perform under the environment of an anechoic chamber. The measuring time or measuring costs will be relatively higher. Moreover, conventional method merely measures radiated emissions of the whole object and is unable to measure the radiated emissions of the object in part. Therefore, the mutual interference between each electronic device within the printed circuit board can not be obtained.